Automatic mechanical burglar-alarm.



A. BRIEOHLE. AUTOMATIC MECHANICAL BURGLAR ALARM. APPLICATION FILED MAY 12, 1910.

990,42& Patented Apr. 25, 1911.

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amnnosros BBIEGHL/E, 6F NEW YQBK, N. Y.

Application filed May 12, 1910.

To all whom it may concern:

Be it known that I, Aimnosics Bnincuns.

' alarm which will be automatic in operation,

the axis of the spindle socket.

and to provide means whereby the device will be tripped, or set in operation, by the movement of a door knob, window frame or like movable part.

Another object of the invention is to provide a simple device by means of ,which the alarm may be rendered inoperative.

A further object of the invention is to provide such iin alarm in the form of a door knob, which, when not in use as an alarm, will serve as an ordinary knob for doors and the like.

With these and other objects in view, the invention will he hereinafter more particularly. described with reference to the accon1-- panying drawings, which form a part of this specification, and will then be pointed out in the claims at the end of the description;

In the drawings, Figure sectional view on the line l-I of Fig. Fig. 2 a sectional view on the line H ll of Fig. 3; and Fig. 3 a longitudinal sectional viewof the bell and easing.

Referring to the various parts by numerals, l designates a socket formed with an angular longitudinal opening 52 to receive the angular end of the knob spindle. The outer end of this socket carries a springreceptacle 3, said receptacle being in the form of a, circular shallow cup, concentric with This receptacle is closed by a plate 4: and contains a s iral spring 5, whose outer end is connectell to a rigid post (3. its inner end being connected to the main operating shaft 7. Carried by the plate 4. is a supporting frame consisting of the posts 8 and a. face plate 9. The shaft 7 extends through the face plate 9 and carries at its outer end a hell it). Between the face plate 8) and the plate 4, the operating shaft 7 is enlarged, said enlargement serving as av means for holding the shaft in position. it wilhofcoursebe understood, however, that said shaft may be 1 is a vertical Specification of Letters Patent.

llatented Apr. 25, ifilti.

Serial No. 580,832.

mounted in any suitable manner; The bell 10 serves as a means for rotating the shaft 7 in the proper direction to wind up the spring for the purpose of setting the alarm.

Secured rigidly to the main operating shaft is a ratchet wheel 11, and loosely mounted on said shaft adjoining said ratchet wheel is a large gear 12, This gear carries a pawl 13 which is adapted to engage the teeth of the ratchet wheel and is held vicldingly in Contact therewith by a spring 14. The ratchet and pawl are so disposed that the she. may turn freely on its axis in the proper direction to wind up the spring 5 but cannot turn in the reverse direction without also rotating the gear 12 through said ratchet and pawl connection. lileshing with the large gear 12 is a small pinion 15', on the shaft 16 of which is carried a spur gear 17. This gear 17 in turn meshes with a small pinion 18, the shaft of which carries a ratchet wheel 19 which serves as an escapcmcnt wheel. It will thus be seen that when the shaft "'4' is free to retate through the influence of the spring 5, itwill carry with it the gear 12 and said gear will operate the escapementwheel through the train of gears just described. in turning the shaft in the proper direction to wind up the spring 5 the pawl 13 will slip on the ratchet.

lflngaging the escapement wheel capcment dog 20 "formed with two teeth 21 and 22, the upper the lower one. as shown clearly in Fig. 1.

late s directly below the center of the shaft 1, the pivot 23 thereof being just above the middle of the dog, whereby the lepei-iding part of said dog is slightly longer than the part above the pivot. The teethot' the es- -.ap(uuent dog are arranged to engage the teeth of the escapement wheel, and the upper tooth 22 is of such length that it will engage the cscapcinent wheel when the escapement dog is in a vertical position, the lower tooth being of such length that it will not engage the escapeinent wheel when the dog isvertical. The teeth are so arranged when. one is in engagement with the escapement wheel the otherone will be released therefrom for a purpose which will fully hereinafter appear.

Below the escapement dog and directly in line with the pivot thereof and the axis of This cscapement dog is pivoted on the face the shaft '1 is a pivoted or swinging locking dog 24, said dog being slightly slotted, radially, at 25, and being pivotally supported on the face plate by a screw 26, said screw passing through the slot and into the face ment 28 ofthe escapement dog, the locking dog is mounted on a transversely extending spring 29, said spring being shown in the -drawings in the form of a wire passing through the locking dog, its ends being rigidly connected to lugs 30 on the face plate.

It will be readily seen that any strain tendmg to swingthe locking dog on its pivot wil be yiel ingly opposed by means of the s ring, said spring permitting the locking 'og to be swung on its pivot when sufficient strain is applied thereto in the properdirection. It isalso manifest that when the strain is removed the spring will return the dog to its normal position radially with respect to the operating shaft. The purpose of the short slot 25 in the locking dog is to permit said do to yield slightly downwardly when it is being returned to its radial position to engage the locking lug 27 under the cam or enlargement 28 on the escapement dog. Stops 31 are provided to hold the locking do released. When said dog is swun lateral y to release the escapementthe en of the lug 27 will bind against the lower side of one of the stops and hold the dog in an inclined position against the tension of the spring 29 until it is forcibly released and returned to its normal vertical posit-ion. Until the do is released fromthe engaged stop 31 the dell will continue to ring, until, of course, the spring is exhausted. j

It .is manifest when the parts are arranged as shown in Fig. 1, the escapement dog and the escapement wheel are locked and there can be no rotative movement of the operating shaft. To release the escapement dog I connect to the lockin do a pivoted latch .32. The lower end 0 theock1i1g dog is bifurcated, and between the two arms thus formed, the latch 32' is mounted on its pivot 33. The lower end of this latch is formed with an aperture to which is connectedan operative cord 34, the other end of said cord being adapted to be connected toa door or to a stationary part of a window frame should the device he used as a window alarm.

To look the alarm in inoperative position, the bell is provided on its inner surface wit-h an annular toothed rack 35, and the u per end of the latch 32 is formed with a loclzing tooth 36 which is adapted to engage the rack when the latch is swung to its inner position as indicated in dotted lines in Fig. 3. To yieldingly hold the latch in position to lock tlle bell a ainst rotation a spring 37 is secured in place by-means of the screw 26, the free end of said spring being in position to engage theend of the latch and to hold it yieldingly in its locked position. The spring receiving cup or barrel -is formed with a recess 38 to receive the outer end of the latch when said latch is thrown to its locked positi on, as shown clearly in Fig. 3. To the upper end of the escapement dog is connected a suitably bent hammer-carrying spring 39, to the outer end ofwhich is connected the hammer 40, said hammer being in position to strike the bell.

The operation of the device may be briefly described as follows. By turning the bell in the direction indicated by the arrow in 2, the spring 5 will be wound upon the sha t.

The escapement wheel, and consequentlythe shaft7, \villhe held against rotative movement by the escapement dog, said dog being held stationary by means ofthe locking lug 27 engaging the cam surface 28. The operating cord 34 is connected to the door 'in any suitable position, the latch 32 being in its radial osition as indicated in Figs. 1 and 9 3. It is, of course, to be understood that the alarm is to be secured to theinner end of a knob spindle, that is to say on the, end which extends into the room, the outer door knob being of the ordinary, or of any suitable construction. With the'parts in the position just described, it is manifest that if the outerv door knob, be turned in either direction, the pull on the operating cord will swing the locking dog on its pivot and against the tension of the spring 29 and will free the locking lug 27 from thecam surface 28 and permit the escapemcnt dog to vibrate under the influence of the escapement wheel. It is manifest that as the escapement dog vibrates the hammer will strike the bell. It is manifest that the bell ringing will continue until the locking dog is again brought into position to bring the locking lug under escapement dog. When the latch 32- is thrown into its locked position, as indicated in .dotted lines in Fig. 3, the alarmmay be used as, and will operate in the same man:

nor, as an ordinary door knob. It is manifest that any suitable form of escapement or bell ringing device may be used, it being only necessary that said ringing device he released by a pull on the lockin dog. -It is also manifest thatany suit-125 ab e form of alarm releasing device may be. employed in place of the specific form of device shown in the herein.

I'have shown the invention as designed ,130

the cam 2am arrest the movement of the 11 drawings and described I i other places than on particularly for use as a door knob. It is manifest that it may be used as an alarm in door knobs without material modification and it is not intended to limit the scope of the present invention to the use thereof simply on door knobs.

Having thus described my invention, 1 claim as new anddesire to secure by Letters Patent 1. A burglar alarm comprising a spring. spring holding'means, a shaft connected to said spring and adapted to be rotated the eby, a bell; carried by said shaft, a hammer operating mechanism operated from said shaft,ja locking dog to hold said mechanism inoperative, a spring arranged within the bell and on which said locking dog is mounted, a latch pivoted to said locking dog, a pull cord connected to said latch, the latch and dog being relatively movable with respect to each other, and means within the bell adapted to be engaged by said latch when it is turned on its pivot to lock the bell against rotation.

2. A burglar alarm comprising a knob spindle socket, a spring a spring receiving cup connected to said socket. a plate closing said cup, a hammer operating mechanism supported on said plate, said mechanism including a train of gears, an escapement and a hammer carried by said escapement, a bell secured to the end of said shaft, a hammer operating mechanismwithin said bell and comprising a train of gears operating from the shaft, an escapement wheel connected to and operated from said train. a pivoted escapement operating on said escapcment wheel, a bell hammer carried by said escapement and adapted to strike the bell when said esca-peinent is vibrated, a locking dog for holding said escapement a straight spring extending through said locking dog, its end being rigidly supported on the closing plate whereby said locking dog will be normally held in a position radially with respect to the operating shaft, a latch pivoted to said locking dog, a pull cord connected to the lower end of said latch and means within the bell adapted to be engaged by said latch when it is turned on its pivot to lock the bell against rotation.

53. A burglar alarm comprisinga knob spindle socket, a spring receiving cup constationary,-

a locking dog formed nected to said socket, a plate closing said cup, a hammer operating mechanism supported on said plate, said mechanism including a train of gears, an escapement and a hammer carried by said escapement, a bell secured to the end of said shaft, a hammer comprising all gears-operating from the operating mechanism within said bell and shaft, an escapement wheel connected to and operated from said train, a pivoted escapeinent operating on said escapement wheel, a hell hammer carried by said escapement and adapted to strike the hell when said escapemcnt, is vibrated. a locking dog for holding said escapement stationary, a straight spring extending through said locking dog, its end being rigidly supported on theclosing plate whereby said locking dog will be normally held in a position radially with respect to the operating shaft. a latch pivoted to said locking dog. a pull cord connected to the lower end of said latch and an annular rack within thebell adapted to be engaged by said latch when it is turned on its pivot to lock the bell against rotation.

4. A'burglar alarm comprising a springcontaining cup. a 'spindle socketconnected thereto. a spiral spring within said cup, a shaft extending into said cup and connected to said spring and adapted to be operated thereby, a plate inclosing said spring. a train of gears supported by said plate and operated from the said shaft. an escapement wheel operated by said train, a pivoted escapement arranged to be operated by said wheel. a hammer carried by said escapement, with a locking lug adapted to engage said escapement' and to hold it against movement, a straight spring extending through the locking dog and rigidly supported at its ends, a pivoted latch connected to said locking dog, the outer end of said latch extending beyond the bell in 

